This intriguing novel contains many hints that could be used to support the view that Billy Pilgrim's experiences, which include becoming "unstuck" in time and also alien abduction, never actually happened in quite the way he perceived them to occur. One of these hints is supplied to us in Chapter 4, when Billy tries to go to sleep in the boxcar, only to find that everybody refuses to have him sleep next to them. When he tries to lie down, the soldiers variously claim that when he sleeps, Billy kicks, whimpers and yells:

And now there was an acrimonious madrigal, with parts sung in all quarters of the car. Nearly everybody, seemingly, had an atrocity story of something Billy Pilgrim had done to him in his sleep. Everybody told Billy Pilgrim to keep the hell away.

The other prisoners of war therefore accuse Billy of shouting, whimpering and moving erratically during his sleep, which are signs of clear emotional distress and turmoil. This leads the reader to question whether Billy actually is literally "unstuck" in time, or whether he merely dreams the incidents that he feels occur to him, and, upon waking, imagines them to have been real.